CVE-2026-46176: RDMA/mlx5: Fix error path fall-through in mlx5_ib_dev_res_srq_init()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-28 · updated 2026-10-19
Weakness: CWE-825

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix error path fall-through in mlx5_ib_dev_res_srq_init() mlx5_ib_dev_res_srq_init() allocates two SRQs, s0 and s1. When ib_create_srq() fails for s1, the error branch destroys s0 but falls through and unconditionally assigns the freed s0 and the ERR_PTR s1 to devr->s0 and devr->s1. This leads to several problems: the lock-free fast path checks "if (devr->s1) return 0;" and treats the ERR_PTR as already initialised; users in mlx5_ib_create_qp() dereference the freed SRQ or ERR_PTR via to_msrq(devr->s0)->msrq.srqn; and mlx5_ib_dev_res_cleanup() dereferences the ERR_PTR and double-frees s0 on teardown. Fix by adding the same `goto unlock` in the s1 failure path.

Affected products

Linux kernel: from 6.6.64 before 6.6.140; from 6.11 before 6.12.88; from 6.13 before 6.18.30; from 6.19 before 7.0.7; 7.1-rc1, 7.1-rc2 — fixed in 6.12.88, 6.18.30, 6.6.140, 7.0.7

How to fix

Upgrade to a fixed version: Linux kernel 6.12.88, 6.18.30, 6.6.140, 7.0.7. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-46176 or the next vulnerability affects your stack